Propulsion of vessels



(Model.)

T. DUNLAP.

PRoPULsIoN 0F VEssELs.

10.321921 Y Patented 0Gt6,18854 Amfwd UNITED STATES PATENT OFFICE.

THOMAS DUNLAP, OF TOLEDO, OHIO.

PROPULSION OF VESSELS.

SPECIFICATION forming part of Letters Patent No. 327,927, dated October 6, 1885.

Application filed November 2S, 1884. Serial No. 149,123. (Model.)

To all whom t may concern:

Be it known that I, THoMAs DUNLAP, a citizen of the United States, residing at Toledo, in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in Navigation, of which the following is a description.

My invention relates to the propulsion of vessels, and is especially adapted for those intended for inland navigation-as on rivers and canals. It consists in certain improvements in the construction and the arrangement of the propeller apparatus, whereby such vessels can be moved in canals and rivers with less washing of the banks than has been attainable heretofore, and yet at avhigher rate of speed in proportion to the power employed than has been heretofore accomplished for such vessels. v

In the accompanying drawings, Figure 1 is a Vertical and central longitudinal section of a vessel to which my improvement is applied. Fig. 2 is a vertical and longitudinal section taken through the center of one of the propellers. Fig. 3 is a vertical cross-section taken through the centers of both propellers. Fig.

4 is an under side view of the bottom of the forward part of the vessel, showing the propeller-chambers and their openings.

Similar letters indicate corresponding parts.

In this example my invention is shown applied to a vessel the hull or body H of which is represented in the drawings. I prefer that the vessel be flat-bottomed and have pointed bows, but do not restrict myself to any particular shape or proportions therefor. Under the bow of the vessel I arrange two horizontal propellers, B B, working in suitable chambers, C C, in the bottoms of which the vertical shaftsS S of the propellers have their bearings. The shafts S S of the propellers project upward through the hull H, so that their upper ends may be suitably connected with an engine or other driving power, so as to revolve the propellers. The shafts S S, in their extension upward, pass through inclosing tubes T T, which extend from the propellerchambers to the necessaryheight so as to give proper protection to the shafts. l

The propeller-chambers O O are separated from each other by a partition, P, which is in line with the keel K, of which it may be considered a continuation, and they are closed on all sides except at the rear ends, R R, where they are open to the water, and at the places marked O O, where quadrant-shaped openings are made in the bottoms of the chambers in the rear of the center lines of the propellershafts, and, observing Fig. 4C, near the outer edges of the chambers. The chambers O O together extend across the entire width of the vessels bottom, and are so shaped in front (see Figs. l and 2) as to incline upward toward the bottom of the vessel and avoid any shoulder or angle where the chambers and the bottom of the vessel join each other.

The openings O O in the bottoms of the chambers are each about equal in area to onequarter of the face or dimensions of the propeller, as shown in Fig. 4..

. The chambers O C are extended backward beyond the propellers far enough to give direction to the water moved by them, so as to cause the water to be moving backward in a right line when emerging from the-rear ends, R R, of the chambers.

If the propellers are arranged to have the direction of their rotation from the front inwardly, then the openings O O are arranged along the inner sides of the rear part of the chambers O O; but in Fig. 4 they are arranged on the outer rear sides of the chambers with the view of rotating the propellers from the front outwardly.

The propellers are each constructed with a disk composing its face, and to the under side of the disk or face are secured-radial arms or blades, whose height and length are determined with reference to the dimensions of the propeller-chambers, so that the propeller can revolve freely therein. The blades are properly stayed and strengthened, so as to be able to resist the strain to which they are subjected.

It will be observed that in my construction the propellers extend across the entire width of the bottom of the boat, and that they are located under its bow, the water which is admitted through the openings O O into the chambers being discharged from the ends R R of the chambers directly under the hull, whereby the relative buoyancy of the boat is increased and the tendency of the boat to produce a swell by its movement through the water is diminished. The chambers C C are of equal heights with the keel, so that the keel i aids in causing the Water that is discharged from the chambers to move backward in a right line.

What I claim as new, and desire to secure by Letters Patent, is-

l. rlhe combination, with a vessel, of propeller-chambers C C, provided with propellers B B, said chambers being arranged under the bow of the vessel on either side of and of equal height with the keel, and having open ends RVR, and openings O O in their bottoms, substantially as described.

` 2. Thehorizontal propellers BB, eachhaving a solid disk for its face and radial blades secured thereto, in combination with the chaml bers C C, which are closed onall sides except at their rear ends, R R, and at the bottom openings, O O, substantially as described.

THOMAS DUNLAP.

Witnesses:

GEORGE S. BRAILEY, J. A. BARBER. 

